RFC: A plan for open source integration tests

[rrnewton]

In the initial release, we have internal (buck, monorepo) integration testing of hermit, but don't yet have an OSS solution for full CI testing.

Our initial plan for building out OSS CI involves these steps:

• Create a .nix expression for a build enivironment with buck[1]
• Create a .buckconfig
• Port tests/TARGETS and tests/helpers.bzl to either use a shims, possibly high-level wrappers for rust_binary,cpp_binary etc.
• Have the tests depend use the cargo-built hermit (target/debug/hermit), rather than attempting to build hermit with buck externally.
• Build a CI script that uses buck build and buck test for these integration tests.
• Make sure it runs locally, and expose an easy validate script that people can call themselves.
• Find or provision an external VM that is configured with perf counters and CPUID to be able to actually run these tests (CircleCI?)

[VladimirMakaev]

Alternatively Docker can be explored heavily here. I actually think it might be easier than dealing with .nix. It should be easy to build a reusable docker image with "buck" as entrypoint that is used as CLI

[rrnewton]

Well, Docker and nix can be used together for sure. Nix (the package manager) is more an alternative to apt-get here. I didn't get the sense from the buck1 website that it is well packaged for distros...